Selection of Trapezoidal Cable Tray Supports

Trapezoidal cable trays should be selected based on load capacity, span length, material suitability, and environmental conditions, with proper support and splice plate placement to ensure safe and reliable installation.

Material Selection

Trapezoidal cable trays are available in steel, stainless steel, aluminum, and pultruded fiberglass. The choice depends on environmental conditions and mechanical requirements:

• Steel: Strong and cost-effective, suitable for indoor and moderate environments. Hot-dip galvanization improves corrosion resistance .
• Stainless Steel (AISI 316L): Ideal for highly corrosive environments, including chemical plants and coastal areas .
• Aluminum: Lightweight with excellent corrosion resistance due to natural oxide formation, suitable for outdoor or humid environments .
• Pultruded Fiberglass: High resistance-to-weight ratio and good corrosion resistance, often used in chemical or offshore applications .

Load Capacity and Span Considerations

The tray must support both cable weight and environmental loads such as wind, snow, or ice. Span selection is critical:

• Short Span: 6–8 feet, typically for indoor installations.
• Intermediate Span: 10–12 feet, common for general industrial use.
• Long Span: 14–20 feet, used outdoors or to reduce support costs.
• Extra-Long Span: Over 20 feet, often for road crossings or large outdoor runs . The distance between supports affects tray strength exponentially, so the tray's mechanical rating must match the chosen span. Splice plates should be installed at tray joints, especially in long or extra-long spans, to maintain structural integrity .

Installation Best Practices

• Support Placement: Ensure supports are aligned with the selected span. Use brackets, hangers, or structural steel attachments suitable for the environment .
• Tray Alignment: Maintain level runs and proper slope for drainage if outdoors. Avoid sharp bends that could stress cables.
• Cable Arrangement: Separate power, control, and data cables where possible to reduce interference. Use dividers if necessary .
• Safety Compliance: Follow standards such as BS EN 61537 for cable trays and BS 6946 for channel support systems. Trapezoidal trays are not walkways and should not support personnel .
• Corrosion Protection: Apply galvanization, powder coating, or select corrosion-resistant materials based on environmental exposure .

Additional Considerations

• Thermal Expansion: Allow for expansion and contraction in long outdoor runs.
• Accessibility: Ensure trays are accessible for maintenance and cable addition.
• Integration: Use compatible fittings, bends, and accessories to maintain system integrity . By carefully selecting the material, span, and support configuration, and following installation best practices, trapezoidal cable trays can provide a durable, safe, and efficient cable management solution for industrial and commercial applications.